Maturity stage at harvest on the chemical composition, fermentation losses, and starch and NDF digestibility of whole-plant corn silages

ABSTRACT This study aimed to evaluate the effects of two maturity stages of whole-plant corn at harvest (32.1 or 42.5% dry matter (DM)) and a commercial microbial inoculant composed of L. buchneri and L. plantarum at concentration of 110,000 CFU/g of fresh forage (1.1 × 105 CFU/g FF) on fermentation losses, aerobic stability, chemical composition, and digestibility of starch and neutral detergent fiber (NDF). A factorial and randomized design was used (two DM contents, both with or without inoculant), with five replicates per treatment. Dry matter at harvest affected most variables, except lignin, NDF digestibility, ethanol, and lactic and acetic acids. Drier silages differed in total DM losses (−1.7%) and lactic acid bacteria (LAB) population (+1.2 log CFU/g). The use of the inoculant affected the levels of ether extract (+0.27% DM), starch (+2.9% DM), and lignin (−0.17% DM). The LAB (+1.6 log CFU/g) and yeast (−2.82% log CFU/g) populations were also influenced, as well as aerobic stability at six days. The inoculant × DM interaction was observed in the water-soluble carbohydrates content, being higher in silages with 32.1% DM and in those not inoculated for both DM. Crude protein was also higher in these silages, whether inoculated or not. Wetter silages were more prone to gas losses when inoculated (+2.5% DM) and lost more effluent when not inoculated (+4.82 kg/t FF). However, total DM losses during aerobic stability were on average 10.58% DM lower in these silages, with inoculation being preferred (6.72% DM vs 11.60% DM (control)). Under these conditions, harvesting corn for silage at 42.5% DM is indicated to obtain a more energetic silage, as noted both in the increased starch content and the reduced losses associated with fermentation.